The footwear industry is an old and crowded art. The industry is constantly attempting to design new products with aesthetic appeal, as well as being comfortable and having ease of construction.
Various designs of slippers have been available for a number of years. See U.S. Pat. No. 5,392,532 (Bray, Jr. et al.) and U.S. Pat. No. 6,226,894 (Bray, Jr. et al.) In general, slippers are a type of footwear having a generally soft construction and are generally washable in a conventional clothes washing machine. Slippers are typically not manufactured using a last, which is often a necessary device when manufacturing a shoe, including a hard sole and a leather upper.
Insoles for various shoes and slippers have been manufactured using compression molding of various polymers. See U.S. Pat. No. 5,551,173 (Chambers) and U.S. Pat. No. 3,766,669 (Pearsall). The insole provides a cushion and support for the foot. The comfort felt by the wearer of a shoe or slipper depends, in large part, on the ability of this foam insole to redistribute the various forces imposed on the foot during walking and standing. These forces are greatest in the heel, arch, and forefoot regions.